| 摘要 |
<p>A light-emitting diode (LED) (1) is used as the light source. The light is focused onto the underside of the sample (4) from below the stage, at a shallow angle of 10[deg]-35[deg]. Instead of a condenser, a concentrator (2) is used for the LED illumination. The concentrator can be height-adjusted for replacement of the condenser. The concentrator focuses the light 1 mm above its tip. The tip (3) includes a depression with a depth of 3-60 mm, located directly below the sample. Further dimensions and details of construction are provided.</p> |
